This past Sunday was a powder morning that turned into a tracked-out powder afternoon. Tuesday was a corduroy morning that turned into a bumpy, choppy afternoon.

An article on the website thesnowchas ers.com describes 22 different types of snow on most slopes. For brevity, I will cover only a handful here — the kind most often found at Mt. Bachelor ski area.

On Sunday, I fought punishing lift lines to enjoy 5 inches of powder that had fallen the night before. Turning through the deep, dry snow on my snowboard was fairly easy, but as the day wore on it became increasingly difficult.

“Powder takes more muscle strength, so maybe you’re not in as good a shape as you were at the end of the previous season,” said Tom Lomax, mountain operations manager at Bachelor. “So it’s something to keep in mind.”

As the day wore on, that changed into tracked-out powder, which is still soft but can be hard on the knees as you ride over the tracks.

“It’s not super flat, but it’s still really soft,” Lomax said of packed powder. “You can still dig into a lot of snow.”

Tuesday on the mountain started with corduroy — those perfectly straight lines formed by the plastic combs on the back of the tiller on the grooming machine. Skiers and boarders can carve with ease on this type of surface, but it gets chewed up as the day goes on. Such was the case Tuesday, when a soft-groomer day turned into a day of trying to avoid bumps and moguls.

Lomax said snowriders should always be aware of changing terrain.

“People are gonna push the snow around all day and start to make small moguls and maybe some ruts and things like that,” he said. “You just ride accordingly. Just be in a good neutral position and be able to adjust to that terrain so you ski over it. I don’t think you necessarily change your skiing a lot, but it’s certainly not going to be as smooth as it was on that first corduroy run of the morning. As you go through the day, a little lighter touch on your skis.”

Lomax said that crust is probably the most difficult type of snow for skiers to negotiate. Crust forms when warming occurs after a recent snowfall. The moisture from the melting snow hardens with colder conditions overnight, Lomax explained. Crust is not so challenging for snowboarders, but for skiers it can pull their skis apart or be “hooky.”

“You have to make a solid platform with your skis, and really focus on keeping that platform through your turn, so you don’t hook one ski and have it pull out,” Lomax said.

He added that most newer skis are wider, which helps skiers tremendously in crust conditions. And newer all-mountain skis are adaptable to a variety of snow types.

“That used to be a much bigger deal before the new skis,” Lomax said of crust.

Icy conditions also occur after several days of no new snow and heavy skier traffic, Lomax noted. That combination can pack the snow and slide all the soft snow off the slopes.

But when skiing ice or hard-pack conditions, skiers can ride their edges.

“The new skis have a defined carving radius built into them,” Lomax said. “On the hard pack, the new skis are just awesome for that. You lay the ski over and let the ski do all the work.”

With no snowfall in the forecast through next week and high temperatures expected to reach the 40s at Bachelor, skiers and riders could be in store for some hard-pack or icy conditions.

“We’re going to see some pretty warm weather this week,” Lomax said. “It’ll probably get harder, but the grooming machines will keep it tilled up and smooth.”

The weather this fall has certainly been interesting at Bachelor. Some 40 inches of snowpack on opening day (Nov. 18) dwindled to 20 inches after several days of warm rain and high winds. The resort was forced to close for a few days before reopening on Nov. 24, and lower-elevation resorts in Central Oregon — Hoodoo Ski Area near Sisters and Willamette Pass — have still not opened.

Bachelor reported a snowpack of 30 inches on Wednesday, and the base remains solid on most of the main runs. But Lomax said more snow is needed to be able to open additional chairlifts, including Cloudchaser and Outback.

Lomax advised snowriders to use extreme caution, especially if riding off the groomed runs. The snowpack is thin enough that riding over exposed rocks, stumps or sudden terrain changes is a constant hazard.

“You have to be very careful right now,” Lomax warned. “There’s all sorts of hazards — things you can see and things you can’t see. It’s not necessarily gonna be a soft landing, if you’re in the woods and there’s a tree blowdown with branches, or a lava ridge that’s not completely covered but it looks covered to you. All those hazards are kind of off the main runs. It’s really a good idea just to start mellow and easy. We’ve got almost a six-month ski season here. You’ve got tons of time.”